/**
 * Copyright (c) <2010>, <SUNNY GUPTA>
 * All rights reserved.

 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of the <ORGANIZATION> nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <SUNNY GUPTA> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.gwtp.investmentadvisor.server.entities.finance;

import java.math.BigDecimal;
import java.util.Currency;
import java.util.Locale;

import com.gwtp.investmentadvisor.server.core.datastore.annotation.NonPersisted;
import com.gwtp.investmentadvisor.server.externaldataservices.CurrencyConverterServiceProvider;
import com.gwtp.investmentadvisor.server.externaldataservices.exception.CurrencyMismatchException;

/**
 * <p>Models a financial amount, with Currency & Amount integral parts</p>
 * <p>Note that this class is not persisted. It's only there for In Memory usage</p>
 * @author Sunny Gupta Gupta
 *
 */
@NonPersisted
public class FinancialAmount {

  private static final BigDecimal DEFAULT_VALUE = BigDecimal.ZERO;

  public FinancialAmount() {
    this.currency = Currency.getInstance(Locale.getDefault());
    this.value = DEFAULT_VALUE;
  }
  
  public FinancialAmount(Currency currency) {
    if (currency == null) {
      this.currency = Currency.getInstance(Locale.getDefault());
    } else {
      this.currency = currency;
    }
    this.value = DEFAULT_VALUE;
  }
  
  public FinancialAmount(Currency currency, BigDecimal value) {
    if (currency == null) {
      this.currency = Currency.getInstance(Locale.getDefault());
    } else {
      this.currency = currency;
    }
    if (value == null) {
      this.value = DEFAULT_VALUE;
    } else {
      this.value = value;
    }
  }
  
  /**
   * This should be called when the Currency needs to be changed.
   * @param currency the currency to set
   * @param currencyConverterServiceProvider the converter to use for conversion. If it's null, no conversion is performed
   */
  public void changeCurrency(Currency currency, CurrencyConverterServiceProvider currencyConverterServiceProvider) {
    // Check for a valid converter
    if (currencyConverterServiceProvider == null) {
      return;
    } else {
      // Get conversion factor
      BigDecimal conversionFactor = currencyConverterServiceProvider.getConversionFactor(this.currency, currency);
      this.value = this.value.multiply(conversionFactor);
    }
  }
  
  /**
   * @return the currency
   */
  public Currency getCurrency() {
    return currency;
  }

  /**
   * @param value the price to set
   */
  public void setValue(BigDecimal value) {
    this.value = value;
  }

  /**
   * @return the price
   */
  public BigDecimal getValue() {
    return value;
  }

  /**
   * Adds a {@link FinancialAmount} value to the current instance
   * @param augend
   * @return
   * @throws CurrencyMismatchException 
   */
  public FinancialAmount add(FinancialAmount augend) throws CurrencyMismatchException {
    // Check for matching currency
    if (this.getCurrency().equals(augend.getCurrency())) {
      this.value = this.value.add(augend.getValue());
    } else {
      throw new CurrencyMismatchException();
    }  

    return this;
  }
  
  private Currency currency;
  
  private BigDecimal value;
}
